1 d3.time.weeks = d3_time_range(d3.time.week, function(date) {

     2   date.setDate(date.getDate() + 7);

     3 }, function(date) {

     4   return ~~((date - new Date(date.getFullYear(), 0, 1)) / 6048e5);

     5 });

     6 

     7 d3.time.weeks.utc = d3_time_range(d3.time.week.utc, function(date) {

     8   date.setUTCDate(date.getUTCDate() + 7);

     9 }, function(date) {

    10   return ~~((date - Date.UTC(date.getUTCFullYear(), 0, 1)) / 6048e5);

    11 });